Calculating device



April 15, 1947. c. 1.. LUDWXG CALCULATING DEVICE Filed Feb. 25, 1944 2 Sheets-Sheet 1 C424 .1}. Zoom e,

INVENTOR.

ATTO ENEY.

April 15, 1947 c. L. LUDWIG CALCULATING DEVICE 2 Sheets-Sheet 2 Filed Feb. 25, 1944 INVENTOR.

ATTOR Y.

Patented Apr. 15, 1947 UNITED STATES PATENT OFFICE 11 Claims.

This invention relates to computing machines and more especially to a pocket size device for addition, measuring, and similar purposes.

An object of the invention is to provide a simple, practical and inexpensive device of the character described.

Another object is to provide a pocket size de vice for addition and analogous computations.

A further object is to provide a device of the character described adapted for measuring lengths and the like,

Another object is to provide a computing device of the character described having compact and extensible means bearing tables, charts or otherindicia.

Other objects and advantages will appear and be brought out more fully in the following specification, reference being had to the accompanying drawings wherein:

Fig. 1 is a side view of an embodiment of my invention.

Fig. 2 is an enlarged view of the same in central section.

Fig. 3 is a view similar to Fig. 2 showing the device in operated position.

Fig. 4 is a perspective view of an actuating member.

Fig. 5 is a fragmentary view of the tape bearing the computing indicia.

Fig. 6 is a side view partially in section of a modified form of the invention.

Fig. 7 is a fragmentary view of the same shown in operated position.

Fig. 8 is a sectional view taken along the line 8-8 of Fig. 6.

Fig. 9 is a fragmentary view of the tape used in the embodiment shown in Figs. 6 to 8, and

Fig. 10 is a face view of a spring element employed in both forms of the invention.

Referring more particularly to the drawings and more especially to Figs. 1 to 5, I show a device having a tubular housing member ID, at one end of which is secured a roller housing element H which provides bearings for a shaft I2, on an external end of which is a winding crank l3. A tape l4 has one end secured on shaft l2 on which it may be Wound by turning crank l3. A tubular housing I5 is slidably associated with housing l0 and is provided with a shouldered end portion l6 which engages a collar I! which has a threaded connection with tubular member H]. A compression spring I8 is positioned in tubular member ID and bears between the said end portion l8 of member l5 and a wall IQ of circular housing ll. Walljl3 is apertured to permit tape I 4 to extend therethrough, and end portion I6 is similarly apertured. Tape I4 is seen to extend through tubular member [5 and through an aperture in a wall 20 of a circular end housing 2| secured to tubular member I5. Tape M has its other end secured to a shaft 22 in housing 2|, which shaft is suitably provided with a coiled spring which winds the end of tape [4 thereon when permitted by the release of locking means to be hereinafter described.

Tape I4 is provided throughout its length with a plurality of equally spaced apertures 23. opposite each of which on the lower side is numerical indicia 24 comprising the numbers 1, 2, 3, 4, 5 etc. A spring catch 25 is suitably secured within member l5 and has a detent 26 which engages apertures 23 as the tape passes thereunder to the right of the detent 26, preventing the return movement of the tape until released by upward movement of a bar 21 which extends through a pair of slots 28 in the wall portion of member l5. A tape clutch or actuating member 29 is positioned in tubular member l5 and comprises an elongated plate 30 having a bent end 3| secured to a pivot rod 32, each end of which extends through an elongated slot 33 in member l5 and secured to a bearing lug 34 on collar l1. Plate 30 is provided with an abutment bar 35 which extends thereacross and a tape aperture engaging pin 36. A pair of bow springs 31 are suitably secured to plate 30 and rest on tape I 4 and serve to retain pin 36 out of engagement with the tape apertures except when member 29 is actuated, as will be presently explained.

A plurality of selector keys 38 are provided, each key comprising a horizontal portion 39 and a vertically extending portion 40, the latter having a suitable finger piece 4|, each finger piece having indicia such as the numerals 1 to 10 respectively, Portions 39 are pivotally mounted at 42 on a shaft 43 suitably secured to the wall portion of member l5. Horizontal portions 39 extend and terminate under one of a plurality of spring leaves 44 which together form a spring element 45 (Fig. 10) suitably secured to end wall 29. Each selector key 38 is formed with an engaging tip 46 adapted when its key 38 is de pressed, to engage abutment bar 35 of clutch member 29. Vertical portions of the keys extend through an enlarged aperture 41 in tubular member 15. Tubular member ID is provided with an enlarged aperture 48 to permit the indicia 24 to be seen therethrough. A tubular housing 49 may. if desired, be secured to housing 2|, and is provided with a retractable spring roller mounted strip 59 bearing suitable indicia such as mathematical tables, formulae, or the like, pertinent to the type of work with which the computing device may be used, Housing 49 may be provided with a pencil end 5 l In Figs. 6 to 9 I show a modified form of my invention comprising a housing 52 having a guide wall 53 and a guide housing 54 for a reciprocable mechanism 55. A shaft 56 is suitably mounted between the side walls of housing 52 and is provided with a clock spring, and secures an end of tape 51 wound thereon. Tape 51 is provided with a plurality of equally spaced apertures 58 and has indicia 59 thereon corresponding toapeI- tures 58, and also has indicia which may rep- 7 resent inches or other units of measure.

Tape engaging clutch member El is pivotally mounted at E2 in the interior of mechanism and is provided with a tape aperture engaging pin 63 and a plurality of springs 64 which normally retain the pin 63 out of engagement with apertures 58. The lower plate portion of mechanism 55 is provided with an aperture through which pin 63 may pass to engage the tape aper tures. Mechanism 55 has an L-shaped end wall 65 which is suitably apertured to permit a pair of springs 65 to extend therethrough, the end of which springs are secured to a pair of screws 5T extending through housing 54 and a pair of pins 68 each secured to a side wall of mech anism 55.

A- spring latch 59 is secured to an end wall of housing 52 and is provided with a tape aperture engaging detent and is' normally in engagement with one of the tape apertures 58. A latch lifting pin H is secured to latch 69 and extends through an aperture 12 in a side wall of housing 54' so as to be manually operable when desired to release detent 70 from the tape apertures to permit the tape to' be r'ewound on shaft 56 after the mechanism has been manipulated. A plurality o'f selector keys sea are provided, said keys being similar to keys 38; each key being provided with a clutch engaging tip 46a to depress the clutch as shown in' Fig. '7. An abutment pin 13 e'iitends between the side walls of housing 54 and through a slot 14 in each side wall of mechanism 55 The upper wall of housing 54' is provided with a suitable opening to permit keys 38 to extend th'e'rethroug'h and a guard M may be secured thereto if desired.

The operation of the invention should be clear from the foregoing description. In the embodiment shown in' Figs. I to 5, when one of the keys is depressed as shown in Fig. 3, tip 46 depresses clutch 29' and tip 36 engages the adjacent tape aperture 23, whereupon housing member l0 may be pushed to the right with respect to hous ing l5, and tape [4 will be moved to the right and wound up' on shaft 22 by the spring action thereof, the tape being moved until abutment bar 35 engages ti'p 66 of the depressed key and thus the distance the tape moves is that corresponding to the number of tape apertures represented by the depressed key, it beingclear that each key tip 46 is offset from the next numbered key tip adistance equal to the spacing between the tape apertures. Housing it! can thereupon be returned to the position shown in Fig. 2, whereupon detent 26 will prevent return movement of the tape which will, during this movement, be unwound from shaft 12 in housing I i. This operation can be repeated which will result in the addition of the numbersrepresented by the keys 38 as selectively used, and the answer can be pr Le) seen through aperture 48 as should be obvious. When it is desired to return the tape to starting position, detent 26 may be released from the tape by upward movement of bar 21 and the tape be permitted to be wound on shaft H by the clock spring secured thereto or by means of crank 13.

he operation of the embodiment of Figs. 6 to 9 is substantially similar. When one of the eys 38a is depressed, tip 46a engages and depresses the free end of clutch Bl, causing tip 63 to engage an aperture of tape 51, whereupon a lateral movement to the left of the key causes mechanism 55 to be similarly moved until the depressedkey strikes abutment pin 13, and the movement of the tape is limited by the intervening distance. Detent 10 engages the tape apertures and permits movement of the tape to the left but prevents its return movement until released therefrom by a lifting of pin 1| manually.

Having described my invention whatI claim is:

l. A device of the character described com prising a casing having indiciaindexing means, a tape roller mounted within said casing having indicia thereon, means to longitudinally move said tape in said casing a selected pre-determined amount, means to lock said tape inmoved position, and means'to return saidtapeto its-original position when said locking means is releasedmaid first means including a slidable member having releasable tape engaging means, and aplurality of pivoted keys each adapted when pivoted to actuate said tape engaging means adifferent amount;

2. A device of the character described comprising a casing having indicia. indexing means, a tape roller mounted within said casing having indicia thereon, means to longitudinally move said tape in said casing a selected pre-determined amount, means to lock said tape in moved position, and means to return said tape to its original position when said locking means is released, said first means including a slidable member having releasable tape engaging means, and a plurality of pivoted keys each adapted when pivoted to actuate said tape engaging means a different amount, and abutment means adapted to engage said keys to limit the movement of said slidable member and said tape to the amount determined by each of said keys.

3. A device of the character described comprising a casing having indicia indexing means, a tape roller mounted within said casing having indicia thereon, means to longitudinally move said tape in said casing a selected pre-determined amount, means to lock said tape in moved position, and means to return said tape to its original position when said locking means is released, said first means including a slidablemember having releasable tape engaging means, and a plurality of keys each adapted to actuate said tap engaging means into tape engaging position, and abutment means adapted to engage said keys to limit the movement of said slidable member and said tape to the amount determined by each of said keys, said keys being disposed different amounts with respect to said abutment means.

4. A device of the character described comprising a casing having indicia indexing means, a tape roller mounted within said casing having indicia thereon, means to longitudinally move said tape in said casing a selected lire-determined amount, means to lock said tape in moved position, and means to return said tape to its original position when said locking means is released, said first means including a slidable member having releasable tape engaging means and an abutment, and a plurality of longitudinally disposed pivoted keys each adapted when pivoted to effect said tape engagement and engage said abutment to limit the movement thereof a different selected amount.

5. A device of the character described having a pair of telescoping casing members one of said members having indicia indexing means, a tape having roller mounting within each of said casing members having indicia thereon, releasable tape engaging means pivotally secured to one of said casing members and having an abutment, a plurality of keys disposed longitudinally at progressive intervals in the other of said casing members, each of said keys adapted to engage said tape engaging means for tape engagement thereof, said keys each having an abutment engaging tip adapted to limit the movement of said tape engaging means to move said tape a selected predetermined amount when said casing members are telescoped.

6. A device of the character described having a pair of telescoping casing members one of said members having indicia indexing means, a tape having roller mounting within each of said casing members having indicia thereon, releasable spring biased tape engaging means pivotally secured to one of said casing members and having an abutment, a plurality of spring mounted keys disposed longitudinally at progressive intervals in the other of said casing members, each of said keys adapted to engage said tape engaging means for tape engagement thereof, said keys each having an abutment engaging tip adapted to limit the movement of said tape engaging means to move said tape a selected predetermined amount when said casing members are telescoped.

7. A device of the character described having a pair of telescoping casing members one of said members having indicia indexing means, a tape having roller mounting within each of said casing members having indicia thereon and provided with a longitudinal series of apertures, releasable tape aperture engaging means pivotally se-' cured to one of said casing members and having an abutment, a plurality of keys disposed longitudinally at progressive intervals in the other of said casing members, each of said keys adapted to engage said tape engaging means for tape engagement thereof, said keys each having an abutment engaging tip adapted to limit the movement of said tape engaging means to move said tape a selected pro-determined amount when said casing members are telescoped.

8. A device of the character described having a pair of telescoping casing members one of said members having indicia indexing means, a tape having roller mounting within each of said casing members having indicia thereon and provided with a longitudinally series of apertures, releasable tape aperture engaging means pivotally secured to one of said casing members and having an abutment, a plurality of keys disposed longitudinally at progressive intervals in the other of said casing members, each of said keys adapted to engage said tape engaging means for tape engagement thereof, said keys each having an abutment engaging tip adapted to limit the movementof said tape engaging means to move said tape a selected pre-determined amount when said casing members are telescoped and means to bias said casing members in extended relation.

9. A device of the character described comprising a casing having indicia indexing means, a tape roller mounted within said casing having indicia thereon, a tape mounted on said roller and having a free end extending externally of the casing, said casing having an abutment extending transversely of the tape, a frame in said casing adapted for slidable movement longitudinally of said tape, a releasable tape engaging member on said frame, and a plurality of keys on said frame progressively disposed longitudinally with respect to said tape, said keys each adapted when actuated to effect tape engagement and to move said frame longitudinally and having an abutment engaging tip whereby to limit movement of said frame in said casing.

10. A device of the character described comprising a casing having indicia indexing means, a tape roller mounted within said casing having indicia thereon, a tape mounted on said roller and having a free end extending externally of the casing, said casing having an abutment extending transversely of the tape, a frame in said casing adapted for slidable movement longitudinally of and adjacent said tape, a releasable tape engaging member on said frame, and a plurality of keys on said frame progressively disposed longitudinally with respect to said tape, said keys each adapted when actuated to elfect tape engagement and to move said frame longitudinally and having an abutment engaging tip whereby to limit movement of said frame in said casing.

11. A device of the character described comprising a casing having indicia indexing means and having a slot, a tape roller mounted within said casing having indicia thereon, a tape mounted on said roller and having a free end extending externally of the casing and provided with a longitudinally disposed series of apertures, said casing having an abutment extending transversely of the tape, a frame in said casing adapted for slidable movement longitudinally of and adjacent said tape, a releasable tape aperture engaging member on said frame, and a plurality of keys on said frame extending through said slot and progressively disposed longitudinally with respect to said tape, said keys each adapted when actuated to effect tape engagement and to move said frame longitudinally and having an abutment engaging tip whereby to limit movement of said frame in said casing.

CARL L. LUDWIG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 493,117 Ritchie Mar. 7, 1893 614,383 Gilbert Nov. 15, 1898 465,120 Webb Dec. 15, 1891 786,282 Goldman Apr. 4, 1905 

